JP2000015835A - Ink jet printer and printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To print a correct image at all times by performing recovery operation of print head surely while suppressing consumption of ink being discharged therefore. SOLUTION: An image is printed on a sheet using a print head 3 ejecting ink from a plurality of ink ejection openings while performing recovery operation where ink uncontributive to image printing is discharged from the print head 3. Recovery operation is performed by setting an ink ejection opening requiring recovery operation among a plurality of ink ejection openings an ink uncontributive to image printing is discharged only from the ink jet opening thus set.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printing apparatus and an ink jet printing method capable of performing a print head recovery process.

[0002]

2. Description of the Related Art Conventionally, in a printing apparatus using an ink jet system, ink is ejected from an ink ejection port toward a print medium by the action of a heater board, a piezoelectric element, or the like provided in a nozzle of a print head. To print images. In such a print head, when the ink in the nozzle dries, the viscosity of the ink increases (hereinafter, referred to as “thickening”), and the ejection of the ink becomes unstable. Therefore, when printing is not performed, the nozzle surface of the print head, that is, the surface on which the ink discharge ports are formed is sealed to prevent the ink from drying and increase the viscosity of the ink.

By the way, during the printing operation, the ink discharge port is always in contact with the outside air, and depending on the image to be printed, a nozzle that does not discharge ink from the ink discharge port (hereinafter, referred to as “non-discharge nozzle”) is generated. I do. The ink in such a non-ejection nozzle gradually increases in viscosity, and may eventually cause an ejection failure of the ink. Therefore, when performing continuous printing over a long period of time, ink that does not contribute to image printing is discharged from all nozzles of the print head, that is, all ink ejection openings, at predetermined intervals, and fresh ink is injected into the nozzles. A refilling process is performed to replace the ink with the thickened ink. In such a recovery process, for example, ink is ejected from the ink ejection port of each nozzle by the action of a heater board or a piezoelectric element installed in each nozzle in the same manner as during normal printing (hereinafter, “preliminary”). Discharge). Preliminarily ejected ink is ejected toward an ink holding member such as a porous material and held by the ink holding member.

[0004] In addition to the preliminary discharge, the print head recovery process includes a process for forcibly discharging ink from the ink discharge port of the print head. The printing apparatus executes a plurality of recovery processes in combination. As a result, the print head is always maintained in an optimum state. As a recovery process for forcibly discharging ink from the ink discharge port of the print head, there is a method of forcibly discharging ink by pressurizing the ink with an ink supply device, or forcibly discharging ink by suctioning the ink.

[0005]

However, in the case of the above-mentioned conventional recovery processing, ink is discharged from all the nozzles regardless of the necessity of the recovery processing for each nozzle. Emissions increased, and there were the following problems.

That is, in the case of a printing apparatus that does not have a configuration in which waste ink generated due to print head recovery processing is recycled as printing ink again, ink is consumed wastefully due to the large amount of discharged ink. Will do. Further, no means is provided for the ink holding member that holds the ink discharged in this way to suck the waste ink held by the ink holding member and store it in a predetermined waste ink tank or the like. In this case, there is a problem that the waste ink held by the ink holding member is likely to be saturated.

SUMMARY OF THE INVENTION It is an object of the present invention to reliably perform a printhead recovery process while always suppressing consumption of ink discharged for the printhead recovery process, and to always print an appropriate image. An object of the present invention is to provide an ink jet printing apparatus and an ink jet printing method that can be used.

[0008]

An ink jet printing apparatus according to the present invention prints an image on a printing medium using a print head capable of discharging ink from a plurality of ink discharge ports, and prints an image from the ink discharge ports. In an inkjet printing apparatus capable of performing a recovery process for discharging ink not contributing to printing, a setting unit that sets an ink ejection port that requires the recovery process from among the plurality of ink ejection ports, Recovery means for discharging ink not contributing to image printing from only the set ink ejection ports.

The ink jet printing method of the present invention comprises:
Ink jet printing method capable of printing an image on a printing medium using a print head capable of discharging ink from a plurality of ink discharge ports, and performing recovery processing for discharging ink not contributing to image printing from the ink discharge ports In, from among the plurality of ink ejection ports, set an ink ejection port that requires the recovery process,
The recovery processing is performed by discharging ink not contributing to printing of an image only from the set ink ejection port.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a sectional view of a full-color ink jet printing apparatus as an embodiment of the present invention. The printing apparatus of the present embodiment includes a sheet feeding device 1,
The apparatus includes a sheet transport device 2, a print head 3, a nozzle surface sealing device 4, a stacker 5, and the like. Hereinafter, their configurations will be described.

The paper feeder 1 supplies paper 12 as a print medium to a printing apparatus main body. The paper feeding device 1 has a tray 11 on which paper 12 is set,
A pickup roller 13 for feeding the sheet 12, conveyance rollers 14 and 15 for guiding the sheet 12 fed by the pickup roller 13 to the sheet conveyance device 2, a separation guide 16 for preventing double feeding of the sheet 12, and a slant of the sheet 12. It is composed of a shutter 17 for correcting a row, and the like. The print head 3 has at least four printheads for printing full-color images.
The print heads 31, 32, 33, and 34 that eject color (black, cyan, magenta, and yellow) inks are provided. Those print heads 31,
32, 33, and 34 are moved up and down by a drive system (not shown) between a retracted position indicated by a solid line in the figure and a print position indicated by a two-dot chain line in the figure.

The lower surface of each of the print heads 31, 32, 33, and 34 is a nozzle surface, that is, a surface on which ink discharge ports are formed. A plurality of nozzles arranged in a row along the front and back sides of the paper surface in FIG. 1 are formed on those nozzle surfaces, and the nozzles form ink ejection ports that open downward in FIG. 1. I have. Print head 3
1, 32, 33, and 34 discharge ink droplets downward from the ink discharge ports by the action of a heater board or a piezoelectric element installed in the nozzle. Hereinafter, the print heads 31, 32, 33, and 34 are collectively referred to as a print head 3.

The nozzle surface sealing device 4 includes a blade 41 for wiping the nozzle surface of the print head 3 and an absorber 42 for absorbing ink forcibly discharged from an ink discharge port by pressurization of ink by an ink supply device. And a cap 43 made of a rubber material for covering the nozzle surface of the print head 3 and sealing the ink discharge port. When the print head 3 is at the retracted position indicated by the solid line in the drawing, the recovery device 6 is moved directly below the print head 3 by a driving system (not shown) as indicated by the solid line in the drawing. When the print head 3 is at the print position indicated by the two-dot chain line in the figure, the recovery device 6 moves in the horizontal direction as shown by the two-dot chain line in the figure and retracts.

FIG. 2 is a plan view of the sheet conveying device 2.
The paper transport device 2 guides the paper 12 to a paper outlet of the printing device, and includes three transport belts 21 a, 21 b, and 21 c that transport the paper 12 (these are collectively referred to as a “transport belt 21”). A motor 22 for generating a driving force for the transport belt 21 and pulleys 23a, 23b, and 23c for driving the transport belt 21 (these are collectively referred to as
A pulley 23), a paper sensor 27 that detects the leading edge of the paper 12, a roller 24 that guides the paper 12 to the transport belt 21, and paper discharge rollers 25 and 26 that guide the paper 12 to the paper exit of the printing apparatus. It is configured. In the transport belts 21a, 21b, and 21c, the portions located immediately below the print heads 31, 32, 33, and 34 are:
The recovery device 6 is bent downward by the driven pulley 28, and is disposed in a space formed by the bent portion.

The recovery device 6 has a structure in which a recovery frame 62 is provided with an ink absorber 61. Absorber 6
1 is formed of a porous material or the like so as to easily absorb the ink. Print heads 31, 32, 3
In the printing operations 3 and 34, the recovery processing is performed without impairing the throughput performance by ejecting ink that does not contribute to the printing of the image toward the absorber 61, that is, preliminary ejection, during the printing operation. In that case, the print head 31,
32, 33, and 34, when a gap (hereinafter, referred to as a "paper interval") between the papers 12 that are continuously conveyed is formed immediately below the paper 12, the image is printed between the papers. Discharges ink that does not contribute. Therefore, the ink passes between the sheets without hitting the sheet 12, and the ink
1 will be accepted.

The stacker 5 is for stocking the paper 12 on which an image has been printed, and includes discharge rollers 51 and 52 for guiding the paper 12 to a discharge tray 53. The paper discharge tray 53 stocks the paper 12.

Next, the operation from the feeding of the paper 12 to the printing of an image and the storage of the printed paper 12 in the stacker 5 will be briefly described with reference to FIG. Paper 12 guided from paper feeder 1 to paper transporter 2
Is guided onto a conveyor belt 21 driven by a motor 22 and a pulley 23. Paper sensor 2
7, the print timing is measured, and the paper 1
2 passes below the print heads 31, 32, 33, 34, as the print heads 31, 32, 3
An image is printed by ejecting ink from 3, 34.
The paper 12 on which the image is printed is guided by the transport belt 21 to paper discharge rollers 25 and 26 driven by a motor 22. The paper 12 is further guided to a paper discharge tray 53 by paper discharge rollers 51 and 52.

FIG. 3 is a flowchart for explaining the recovery processing before the start of printing.

First, after a print command is issued (step S1), the recovery device 4 performs a pre-print recovery operation of the print head 3, that is, discharges ink not contributing to printing of an image from the ink discharge port before starting printing. A recovery operation (step S2) is performed. Thereafter, the print head 3 moves from the retreat position indicated by the solid line in FIG. 1 to the print position indicated by the two-dot chain line in FIG. 1 (step S3), and starts a printing operation (step S4) for discharging ink for printing an image. . Then, after the end of the continuous printing operation, the print head 3 returns to the retracted position indicated by the solid line in FIG. 1 (step S5), and ends the printing (step S6).

FIG. 4 is a flowchart for explaining a preliminary ejection recovery process interrupted during a continuous printing operation (step S4).

First, the continuous time T of the printing operation is compared with a predetermined reference time Tk (step S7). If the continuous time T of the printing operation does not exceed the reference time Tk, the flow returns to the flow of FIG.

On the other hand, if the continuous time T of the printing operation exceeds the reference time Tk, a pre-ejection recovery command (step S8) is issued, and in step S9, the pre-ejection recovery is executed until the next pre-ejection recovery is executed. Read the image data to be printed. That is, after the later-described preliminary ejection recovery (steps S14 and S15) executed this time, the same preliminary ejection recovery executed next time (steps S14 and S15).
During this period, image data to be printed on the paper 12 (hereinafter referred to as “image data to be printed”) is read. Then, based on the image data to be printed, a nozzle for ejecting ink to print the image is determined (step S10), and the nozzle is determined as a nozzle requiring recovery processing. The nozzles requiring recovery are determined for all the print heads 31, 32, 33, and 34. Then, only the nozzles requiring the recovery are set as the preliminary discharge recovery nozzles for performing the preliminary discharge recovery (step S11).

Then, the leading end of the paper 12 to be conveyed next is detected by the paper sensor 27 (step S1).
2) After the rear end of the paper 12 conveyed before passing through a position facing a black ink discharge print head (hereinafter, referred to as “black head”) 31 (step S13), the paper 12 Preliminary ejection recovery is performed by ejecting ink not contributing to image printing from the black head 31 toward the paper interval (step S14). that time,
The black head 31 discharges ink that does not contribute to image printing from only the preliminary discharge recovery nozzle set in the previous step S11. Therefore, the nozzles to be subjected to the preliminary ejection recovery are limited to only the preliminary ejection recovery nozzles. Similarly, the trailing edge of the paper 12 is
Each time the paper passes through the lower position of 2, 33, 34, the image is printed from the preliminary ejection recovery nozzles of the print heads 32, 33, 34 set in the previous step S11 toward the space between the papers 12. Preliminary ejection recovery is performed by ejecting ink that does not contribute to the above (step S15).

In this manner, every time the continuous time T of the printing operation exceeds the reference time Tk, ink not contributing to the printing of an image is ejected from the nozzles of the print head 3 in accordance with the passage between the sheets 12. Then, preliminary ejection recovery is performed.
In this case, as described above, the preliminary ejection is performed by ejecting ink only from the nozzles that are to eject ink during the period until the next preliminary ejection recovery. Therefore, it is possible to avoid non-ejection of ink while suppressing the amount of ink ejected for the recovery process.

The timing of the operation for limiting the preliminary ejection recovery nozzle as in steps S8 to S11 is not limited to the above-described timing, but may be any timing before executing the preliminary ejection recovery. . As a criterion for the execution timing of the preliminary ejection recovery, other than the time parameter as described above, other parameters may be used, or a plurality of parameters may be combined. As the parameter, for example, an integrated value of the ink ejection amount can be used.

(Second Embodiment) FIG. 5 is a flowchart for explaining another embodiment of the preliminary ejection recovery process interrupted during the printing operation (step S4) of FIG. The same processing steps as those in the embodiment of FIG. 4 described above are denoted by the same step numbers, and description thereof is omitted.

In the case of this example, the continuous time T of the printing operation
Exceeds the reference time Tk, the processing steps S16 and S17 from the issuance of the prefire recovery command (step S8) to the setting of the prefire recovery nozzle (step S11).
Is different from the embodiment of FIG. 4 described above. That is, in step S16, the previous preliminary ejection recovery (or
The image data printed on the sheet 12 (hereinafter, referred to as “previous ejection recovery” (steps S14 and S15) to be performed this time after the previous recovery processing is performed) is performed.
(Called "printed image data"). In step S17, based on the printed image data, the number of ink ejections of each nozzle that has ejected ink for printing the image is obtained, and the number of ink ejections is less than a predetermined reference number n. The recovered nozzle is determined, and the nozzle is determined as a required recovery nozzle that requires recovery processing. That is, for nozzles that have ejected ink more than a reference number n that does not require pre-ejection recovery after the previous preliminary ejection recovery, that is, nozzles that have ejected ink at a predetermined amount or more that do not require pre-ejection recovery, recovery is necessary. The nozzles are excluded from the target of the nozzles, and the other nozzles are set as the nozzles requiring recovery. The nozzles requiring recovery are determined for all the print heads 31, 32, 33, and 34.

After all, in the case of this example, during the period from the previous preliminary ejection recovery (or another previous recovery process) to the current preliminary ejection recovery, the number of ink ejections is less than the predetermined reference number n. Preliminary ejection is performed by ejecting ink only from the missing nozzles. Therefore, similarly to the above-described embodiment, non-ejection of ink can be avoided while suppressing the amount of ink ejected for the recovery process.

(Third Embodiment) FIG. 6 is a flowchart for explaining still another embodiment of the preliminary ejection recovery process interrupted during the printing operation (step S4) of FIG. The same processing steps as those in the embodiment of FIGS. 4 and 5 described above are denoted by the same step numbers, and description thereof is omitted.

In the case of this example, the first and second embodiments described above are combined. That is, first, similarly to the first embodiment of FIG. 4 described above, image data to be printed is read in step S9, and in step S10, nozzles for ejecting ink to print the image are determined. Thereafter, similarly to the above-described second embodiment of FIG. 5, the printed image data is read in step S16, and in step S17, the number of ink ejections of each nozzle that has ejected ink to print the image. Is calculated, and the nozzles whose number of times of ink ejection is less than a predetermined reference number n are determined. Then, the nozzle determined in step S10 and also determined in step S17 is set as a recovery required nozzle requiring recovery processing, and only the recovery required nozzle is set as a preliminary discharge recovery nozzle for performing preliminary discharge recovery. (Step S11).

As described above, only the nozzles that satisfy the above-described conditions for determining the nozzles requiring recovery in the first embodiment and the conditions for determining the nozzles requiring recovery in the second embodiment are set as preliminary ejection recovery nozzles. . Therefore, in step S16, for the nozzles identified as the nozzles that need to be recovered in step S10, the nozzles that need to be recovered can be determined from the nozzles.

A nozzle that satisfies at least one of the above-described conditions for determining a nozzle requiring recovery in the first embodiment and the conditions for determining a nozzle requiring recovery in the second embodiment is set as a preliminary ejection recovery nozzle. You may.

(Others) It should be noted that the present invention includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for discharging ink, particularly in an ink jet printing system. An excellent effect is obtained in a print head (hereinafter, also referred to as a "recording head") and a printing apparatus (hereinafter, also referred to as a "recording apparatus") of a type in which the state of ink is changed by the thermal energy. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method is a so-called on-demand type,
Although it can be applied to any type of continuous type, in particular, in the case of the on-demand type, it can be applied to a sheet holding liquid (ink) or an electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding the nucleate boiling, heat energy is generated in the electrothermal transducer, and film boiling occurs on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal on a one-to-one basis.
This is effective because air bubbles inside can be formed. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination configuration (a linear liquid flow path or a right-angled liquid flow path) of a discharge port, a liquid path, and an electrothermal converter as disclosed in the above-mentioned respective specifications, U.S. Pat. No. 4,558,333 and U.S. Pat.
A configuration using the specification of Japanese Patent No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an aperture for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration is based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium on which a recording apparatus can record, as in the above-described embodiment. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head.

In addition, a serial type recording apparatus, that is, a recording apparatus for recording an image by reciprocating a recording head in a main scanning direction and conveying a recording medium in a sub-scanning direction intersecting the main scanning direction. The present invention is also effective. In this case, a recording head fixed to the apparatus main body,
Alternatively, a replaceable chip-type recording head that can be electrically connected to the apparatus main body or supplied with ink from the apparatus main body by being attached to the apparatus main body, or an ink tank is provided integrally with the recording head itself A cartridge type recording head can be used.

Further, it is preferable to add ejection recovery means for the recording head, preliminary auxiliary means, and the like as the configuration of the recording apparatus of the present invention since the effects of the present invention can be further stabilized. If these are specifically mentioned, the recording head is heated using capping means, cleaning means, pressurizing or suction means, an electrothermal transducer, another heating element or a combination thereof. Pre-heating means for performing the pre-heating and pre-discharging means for performing the discharging other than the recording can be used.

The type and number of recording heads to be mounted are, for example, different from those provided with only one corresponding to a single color ink and those corresponding to a plurality of inks having different recording colors and densities. A plurality may be provided. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, but may be any of integrally forming a printing head or a combination of a plurality of printing heads. The present invention is also very effective for an apparatus provided with at least one of the recording modes of full color by color mixture.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which softens or liquefies at room temperature may be used. In general, the ink jet method generally controls the temperature of the ink itself within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. Sometimes, the ink may be in a liquid state. In addition, in order to positively prevent temperature rise due to thermal energy by using it as energy for changing the state of the ink from a solid state to a liquid state, or to prevent evaporation of the ink, the ink is solidified in a standing state and heated. May be used. In any case, the application of heat energy causes the ink to be liquefied by the application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start solidifying when it reaches the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used. In such a case, the ink
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent Publication No. 1260, it is also possible to adopt a form in which the sheet is opposed to the electrothermal converter in a state where it is held as a liquid or solid substance in the concave portion or through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, the form of the ink jet recording apparatus of the present invention is not only used as an image output terminal of an information processing apparatus such as a computer, but also for a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmitting / receiving function. It may take a form.

[0043]

As described above, according to the present invention, the consumption of the ink discharged for the printhead recovery process is determined by specifying the ink discharge port for discharging the ink for the printhead recovery process. The print head recovery process can be reliably performed while suppressing the amount, so that an appropriate image can always be printed.

In particular, when there is no arrangement for recycling the waste ink discharged for the print head recovery processing, the consumption of ink not contributing to image printing is suppressed, and the running cost is reduced. Can be. Further, the ink holding member holding the waste ink discharged for the print head recovery process may be configured to suck the waste ink held by the ink holding member and store the sucked ink in a predetermined waste ink tank or the like. If no means is provided, the time until the waste ink held by the ink holding member becomes saturated is extended, and if a waste ink tank is provided, the waste ink tank is replaced. The cycle can be lengthened and the maintainability can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an inkjet printing apparatus according to a first embodiment of the present invention.

FIG. 2 is a plan view of a sheet conveying device in the inkjet printing apparatus of FIG.

FIG. 3 is a flowchart illustrating a recovery process before starting printing in the first embodiment of the present invention.

FIG. 4 is a flowchart illustrating a preliminary ejection recovery process according to the first embodiment of the present invention.

FIG. 5 is a flowchart illustrating a preliminary ejection recovery process according to a second embodiment of the present invention.

FIG. 6 is a flowchart illustrating a preliminary ejection recovery process according to a third embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 paper feeder 2 paper transporter 3 printhead 4 sealing device 5 stacker 6 recovery device 61 absorber 62 recovery frame

Claims (13)

[Claims] 1. A recovery process for printing an image on a printing medium using a print head capable of discharging ink from a plurality of ink discharge ports, and discharging ink not contributing to printing of the image from the ink discharge ports. In a possible ink jet printing apparatus, setting means for setting an ink ejection port requiring the recovery process from among the plurality of ink ejection ports, and printing of an image only from the ink ejection port set by the setting means. An ink jet printing apparatus comprising: a recovery unit that discharges ink that does not contribute. 2. The method according to claim 1, wherein the setting unit sets an ink ejection port for ejecting an ink to print an image as an ink ejection port requiring the recovery process between a current recovery process and a next recovery process. The inkjet printing apparatus according to claim 1, wherein: 3. The method according to claim 1, wherein the setting unit sets an ink discharge port for discharging ink to print the image based on image data for printing the image between a current recovery process and a next recovery process. 3. The ink jet printing apparatus according to claim 2, wherein the ink ejection port that requires a recovery process is set. 4. The method according to claim 1, wherein the setting unit sets an ink discharge port that does not discharge a predetermined amount of ink or more between the previous recovery processing and the current recovery processing as an ink discharge port that requires the recovery processing. The inkjet printing apparatus according to claim 1, wherein the printing is performed. 5. The image forming apparatus according to claim 1, wherein the setting unit is configured to set an ink discharge port that has not discharged a predetermined amount or more of ink based on image data when an image is printed during a period from a previous recovery process to a current recovery process. The ink jet printing apparatus according to claim 4, wherein the ink ejection port that requires a recovery process is set. 6. The method according to claim 1, wherein the setting unit is configured to cause the ink ejection ports that have not ejected ink a predetermined number of times or more from the previous recovery processing to the current recovery processing to eject ink that has not ejected a predetermined amount or more of ink. An outlet is provided.
Or the inkjet printing apparatus according to 5. 7. The setting means is an ink ejection port for ejecting ink to print an image between a current recovery process and a next recovery process, and from a previous recovery process to a current recovery process. 2. The ink jet recording method according to claim 1, wherein the ink discharge port that does not discharge a predetermined amount or more of the ink during the period is specified, and the ink discharge port is set as the ink discharge port that requires the recovery process. Printing device. 8. The ink jet printing apparatus according to claim 1, wherein the recovery unit discharges ink from the ink discharge port in the same manner as when printing an image. 9. The ink jet printing apparatus according to claim 1, further comprising an ink absorber for receiving ink not contributing to printing of an image ejected from said ink ejection port. 10. The ink-jet printing apparatus according to claim 1, wherein the recovery unit performs the recovery processing based on a timing every time a predetermined time elapses in a printing operation. 11. A print head, comprising: a transport unit configured to transport the print medium, wherein the print head has the plurality of ink ejection ports formed in a row along a direction intersecting a transport direction of the print medium. The inkjet printing apparatus according to any one of claims 1 to 10, wherein: 12. The ink jet printing apparatus according to claim 1, wherein the print head has an electrothermal converter that generates thermal energy for discharging ink. 13. A recovery process for printing an image on a print medium using a print head capable of discharging ink from a plurality of ink discharge ports, and discharging ink not contributing to image printing from the print head. In an inkjet printing method, an ink ejection port that requires the recovery process is set from the plurality of ink ejection ports, and ink that does not contribute to image printing is discharged only from the set ink ejection port. An ink-jet printing method comprising performing the recovery process.